There were a number of conversations back and forth, so I'd like to see if
1. We can store our ebooks on a DNS-323
2. Either launch the calibre-server on the DNS or
3. keep our metadata file on a local machine, but have it reference the book folders on the server.

CALIBRE_OVERRIDE_DATABASE_PATH - allows you to specify the full path to metadata.db. Using this variable you can have metadata.db be in a location other than the library folder. Useful if your library folder is on a networked drive that does not support file locking.

to point the DB to your local drive while having the library on the DNS-323?

I would set my CALIBRE_OVERRIDE_DATABASE_PATH to be "c:\mybooks", right?

I'm not clear on how to have the books reside on a folder different than the metadata.db. How do I add them?

I made the change to the environment variable, opened Calibre and was told the library database appears to be corrupted. There were/are not books in it. What did I miss?
And now I can't get into Calibre at all. When I select 'Yes' to the rebuild, this is what I get.

That is not quite right. The path includes the database filename so in your case this means it should be set to c:\mybooks\metadata.db

That worked better.. now i can get into the library.

Maybe I'm misunderstanding the environment variable.

I've got the variable set for a local drive c:\mybooks\metadata.db
I've to the actual .epubs on a NAS drive "z:\shared\ebooks"

If I add a epub from the Z drive, it does show up in my library, but it is also copied to my c:\mybooks folder. I was expecting that the book would NOT be copied to the c:\mybooks, but rather referenced by the Library and reside on the Z:\shared\ebooks folder.

I'm sure I missed something, but right now it doesn't seem much different than if I had all the ebooks on my local drive...